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/*
* Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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package com.sun.javafx.scene.control.skin;
import java.util.ArrayList;
import javafx.animation.KeyFrame;
import javafx.animation.Timeline;
import javafx.application.ConditionalFeature;
import javafx.beans.InvalidationListener;
import javafx.beans.Observable;
import javafx.beans.property.BooleanProperty;
import javafx.beans.property.BooleanPropertyBase;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.event.Event;
import javafx.event.EventDispatchChain;
import javafx.event.EventDispatcher;
import javafx.event.EventHandler;
import javafx.geometry.Orientation;
import javafx.scene.Group;
import javafx.scene.Node;
import javafx.scene.Parent;
import javafx.scene.control.Cell;
import javafx.scene.control.IndexedCell;
import javafx.scene.control.ScrollBar;
import javafx.scene.input.MouseEvent;
import javafx.scene.input.ScrollEvent;
import javafx.scene.input.TouchEvent;
import javafx.scene.layout.Region;
import javafx.scene.layout.StackPane;
import javafx.scene.shape.Rectangle;
import javafx.util.Callback;
import javafx.util.Duration;
import com.sun.javafx.PlatformUtil;
import com.sun.javafx.application.PlatformImpl;
/**
* Implementation of a virtualized container using a cell based mechanism.
*/
public class VirtualFlow extends Region {
private boolean touchDetected = false;
private boolean mouseDown = false;
/**
* There are two main complicating factors in the implementation of the
* VirtualFlow, which are made even more complicated due to the performance
* sensitive nature of this code. The first factor is the actual
* virtualization mechanism, wired together with the PositionMapper.
* The second complicating factor is the desire to do minimal layout
* and minimal updates to CSS.
*
* Since the layout mechanism runs at most once per pulse, we want to hook
* into this mechanism for minimal recomputation. Whenever a layout pass
* is run we record the width/height that the virtual flow was last laid
* out to. In subsequent passes, if the width/height has not changed then
* we know we only have to rebuild the cells. If the width or height has
* changed, then we can make appropriate decisions based on whether the
* width / height has been reduced or expanded.
*
* In various places, if requestLayout is called it is generally just
* used to indicate that some form of layout needs to happen (either the
* entire thing has to be reconstructed, or just the cells need to be
* reconstructed, generally).
*
* The accumCell is a special cell which is used in some computations
* when an actual cell for that item isn't currently available. However,
* the accumCell must be cleared whenever the cellFactory function is
* changed because we need to use the cells that come from the new factory.
*
* In addition to storing the lastWidth and lastHeight, we also store the
* number of cells that existed last time we performed a layout. In this
* way if the number of cells change, we can request a layout and when it
* occurs we can tell that the number of cells has changed and react
* accordingly.
*
* Because the VirtualFlow can be laid out horizontally or vertically a
* naming problem is present when trying to conceptualize and implement
* the flow. In particular, the words "width" and "height" are not
* precise when describing the unit of measure along the "virtualized"
* axis and the "orthogonal" axis. For example, the height of a cell when
* the flow is vertical is the magnitude along the "virtualized axis",
* and the width is along the axis orthogonal to it.
*
* Since "height" and "width" are not reliable terms, we use the words
* "length" and "breadth" to describe the magnitude of a cell along
* the virtualized axis and orthogonal axis. For example, in a vertical
* flow, the height=length and the width=breadth. In a horizontal axis,
* the height=breadth and the width=length.
*
* These terms are somewhat arbitrary, but chosen so that when reading
* most of the below code you can think in just one dimension, with
* helper functions converting width/height in to length/breadth, while
* also being different from width/height so as not to get confused with
* the actual width/height of a cell.
*/
/**
* Indicates the primary direction of virtualization. If true, then the
* primary direction of virtualization is vertical, meaning that cells will
* stack vertically on top of each other. If false, then they will stack
* horizontally next to each other.
*/
private BooleanProperty vertical;
public final void setVertical(boolean value) {
verticalProperty().set(value);
}
public final boolean isVertical() {
return vertical == null ? true : vertical.get();
}
public final BooleanProperty verticalProperty() {
if (vertical == null) {
vertical = new BooleanPropertyBase(true) {
@Override protected void invalidated() {
pile.clear();
sheetChildren.clear();
cells.clear();
numCellsVisibleOnScreen = -1;
lastWidth = lastHeight = maxPrefBreadth = -1;
viewportBreadth = viewportLength = lastPosition = 0;
hbar.setValue(0);
vbar.setValue(0);
setPosition(0.0f);
setNeedsLayout(true);
requestLayout();
}
@Override
public Object getBean() {
return VirtualFlow.this;
}
@Override
public String getName() {
return "vertical";
}
};
}
return vertical;
}
/**
* Indicates whether the VirtualFlow viewport is capable of being panned
* by the user (either via the mouse or touch events).
*/
private boolean pannable = true;
public boolean isPannable() { return pannable; }
public void setPannable(boolean value) { this.pannable = value; }
/**
* Indicates the number of cells that should be in the flow. The user of
* the VirtualFlow must set this appropriately. When the cell count changes
* the VirtualFlow responds by updating the visuals. If the items backing
* the cells change, but the count has not changed, you must call the
* reconfigureCells() function to update the visuals.
*/
private int cellCount;
public int getCellCount() { return cellCount; }
public void setCellCount(int i) {
int oldCount = cellCount;
this.cellCount = i;
boolean countChanged = oldCount != cellCount;
// ensure that the virtual scrollbar adjusts in size based on the current
// cell count.
if (countChanged) {
VirtualScrollBar lengthBar = isVertical() ? vbar : hbar;
lengthBar.setMax(i);
}
// I decided *not* to reset maxPrefBreadth here for the following
// situation. Suppose I have 30 cells and then I add 10 more. Just
// because I added 10 more doesn't mean the max pref should be
// reset. Suppose the first 3 cells were extra long, and I was
// scrolled down such that they weren't visible. If I were to reset
// maxPrefBreadth when subsequent cells were added or removed, then the
// scroll bars would erroneously reset as well. So I do not reset
// the maxPrefBreadth here.
// Fix for RT-12512, RT-14301 and RT-14864.
// Without this, the VirtualFlow length-wise scrollbar would not change
// as expected. This would leave items unable to be shown, as they
// would exist outside of the visible area, even when the scrollbar
// was at its maximum position.
// FIXME this should be only executed on the pulse, so this will likely
// lead to performance degradation until it is handled properly.
if (countChanged) {
layoutChildren();
// Fix for RT-13965: Without this line of code, the number of items in
// the sheet would constantly grow, leaking memory for the life of the
// application. This was especially apparent when the total number of
// cells changes - regardless of whether it became bigger or smaller.
sheetChildren.clear();
Parent parent = getParent();
if (parent != null) parent.requestLayout();
}
// TODO suppose I had 100 cells and I added 100 more. Further
// suppose I was scrolled to the bottom when that happened. I
// actually want to update the position of the mapper such that
// the view remains "stable".
}
/**
* The position of the VirtualFlow within its list of cells. This is a value
* between 0 and 1.
*/
private double position;
public double getPosition() {
return position;
}
public void setPosition(double newPosition) {
boolean needsUpdate = this.position != newPosition;
this.position = com.sun.javafx.Utils.clamp(0, newPosition, 1);;
if (needsUpdate) {
requestLayout();
}
}
/**
* For optimisation purposes, some use cases can trade dynamic cell length
* for speed - if fixedCellSize is greater than zero we'll use that rather
* than determine it by querying the cell itself.
*/
private double fixedCellSize = 0;
private boolean fixedCellSizeEnabled = false;
public void setFixedCellSize(final double value) {
this.fixedCellSize = value;
this.fixedCellSizeEnabled = fixedCellSize > 0;
layoutChildren();
}
/**
* Callback which is invoked whenever the VirtualFlow needs a new
* IndexedCell. The VirtualFlow attempts to reuse cells whenever possible
* and only creates the minimal number of cells necessary.
*/
private Callback createCell;
public Callback getCreateCell() { return createCell; }
public void setCreateCell(Callback cc) {
this.createCell = cc;
if (createCell != null) {
accumCell = null;
setNeedsLayout(true);
recreateCells();
if (getParent() != null) getParent().requestLayout();
}
}
/**
* The number of cells on the first full page. This is recomputed whenever
* the viewportLength changes, and is used for computing the visibleAmount
* of the lengthBar.
*/
private int numCellsVisibleOnScreen = -1;
/**
* The maximum preferred size in the non-virtual direction. For example,
* if vertical, then this is the max pref width of all cells encountered.
*
* In general, this is the largest preferred size in the non-virtual
* direction that we have ever encountered. We don't reduce this size
* unless instructed to do so, so as to reduce the amount of scroll bar
* jitter. The access on this variable is package ONLY FOR TESTING.
*/
double maxPrefBreadth;
/**
* The breadth of the viewport portion of the VirtualFlow as computed during
* the layout pass. In a vertical flow this would be the same as the clip
* view width. In a horizontal flow this is the clip view height.
* The access on this variable is package ONLY FOR TESTING.
*/
double viewportBreadth;
/**
* The length of the viewport portion of the VirtualFlow as computed
* during the layout pass. In a vertical flow this would be the same as the
* clip view height. In a horizontal flow this is the clip view width.
* The access on this variable is package ONLY FOR TESTING.
*/
double viewportLength;
/**
* The width of the VirtualFlow the last time it was laid out. We
* use this information for several fast paths during the layout pass.
*/
double lastWidth = -1;
/**
* The height of the VirtualFlow the last time it was laid out. We
* use this information for several fast paths during the layout pass.
*/
double lastHeight = -1;
/**
* The number of "virtual" cells in the flow the last time it was laid out.
* For example, there may have been 1000 virtual cells, but only 20 actual
* cells created and in use. In that case, lastCellCount would be 1000.
*/
int lastCellCount = 0;
/**
* We remember the last value for vertical the last time we laid out the
* flow. If vertical has changed, we will want to change the max & value
* for the different scroll bars. Since we do all the scroll bar update
* work in the layoutChildren function, we need to know what the old value for
* vertical was.
*/
boolean lastVertical;
/**
* The position last time we laid out. If none of the lastXXX vars have
* changed respective to their values in layoutChildren, then we can just punt
* out of the method (I hope...)
*/
double lastPosition;
/**
* The breadth of the first visible cell last time we laid out.
*/
double lastCellBreadth = -1;
/**
* The length of the first visible cell last time we laid out.
*/
double lastCellLength = -1;
/**
* The list of cells representing those cells which actually make up the
* current view. The cells are ordered such that the first cell in this
* list is the first in the view, and the last cell is the last in the
* view. When pixel scrolling, the list is simply shifted and items drop
* off the beginning or the end, depending on the order of scrolling.
*
* This is package private ONLY FOR TESTING
*/
final ArrayLinkedList cells = new ArrayLinkedList();
/**
* A structure containing cells that can be reused later. These are cells
* that at one time were needed to populate the view, but now are no longer
* needed. We keep them here until they are needed again.
*
* This is package private ONLY FOR TESTING
*/
final ArrayLinkedList pile = new ArrayLinkedList();
/**
* A special cell used to accumulate bounds, such that we reduce object
* churn. This cell must be recreated whenever the cell factory function
* changes. This has package access ONLY for testing.
*/
T accumCell;
/**
* This group is used for holding the 'accumCell'. 'accumCell' must
* be added to the skin for it to be styled. Otherwise, it doesn't
* report the correct width/height leading to issues when scrolling
* the flow
*/
Group accumCellParent;
/**
* The group which holds the cells.
*/
final Group sheet;
final ObservableList sheetChildren;
/**
* The scroll bar used for scrolling horizontally. This has package access
* ONLY for testing.
*/
private VirtualScrollBar hbar = new VirtualScrollBar(this);
final VirtualScrollBar getHbar() {
return hbar;
}
/**
* The scroll bar used to scrolling vertically. This has package access
* ONLY for testing.
*/
private VirtualScrollBar vbar = new VirtualScrollBar(this);
final VirtualScrollBar getVbar() {
return vbar;
}
/**
* Control in which the cell's sheet is placed and forms the viewport. The
* viewportBreadth and viewportLength are simply the dimensions of the
* clipView. This has package access ONLY for testing.
*/
ClippedContainer clipView;
/**
* When both the horizontal and vertical scroll bars are visible,
* we have to 'fill in' the bottom right corner where the two scroll bars
* meet. This is handled by this corner region. This has package access
* ONLY for testing.
*/
StackPane corner;
// used for panning the virtual flow
private double lastX;
private double lastY;
private boolean isPanning = false;
public VirtualFlow() {
getStyleClass().add("virtual-flow");
setId("virtual-flow");
// initContent
// --- sheet
sheet = new Group();
sheet.getStyleClass().add("sheet");
sheet.setAutoSizeChildren(false);
sheetChildren = sheet.getChildren();
// --- clipView
clipView = new ClippedContainer(this);
clipView.setNode(sheet);
getChildren().add(clipView);
// --- accumCellParent
accumCellParent = new Group();
accumCellParent.setVisible(false);
getChildren().add(accumCellParent);
/*
** don't allow the ScrollBar to handle the ScrollEvent,
** In a VirtualFlow a vertical scroll should scroll on the vertical only,
** whereas in a horizontal ScrollBar it can scroll horizontally.
*/
final EventDispatcher blockEventDispatcher = new EventDispatcher() {
@Override public Event dispatchEvent(Event event, EventDispatchChain tail) {
// block the event from being passed down to children
return event;
}
};
// block ScrollEvent from being passed down to scrollbar's skin
final EventDispatcher oldHsbEventDispatcher = hbar.getEventDispatcher();
hbar.setEventDispatcher(new EventDispatcher() {
@Override public Event dispatchEvent(Event event, EventDispatchChain tail) {
if (event.getEventType() == ScrollEvent.SCROLL &&
!((ScrollEvent)event).isDirect()) {
tail = tail.prepend(blockEventDispatcher);
tail = tail.prepend(oldHsbEventDispatcher);
return tail.dispatchEvent(event);
}
return oldHsbEventDispatcher.dispatchEvent(event, tail);
}
});
// block ScrollEvent from being passed down to scrollbar's skin
final EventDispatcher oldVsbEventDispatcher = vbar.getEventDispatcher();
vbar.setEventDispatcher(new EventDispatcher() {
@Override public Event dispatchEvent(Event event, EventDispatchChain tail) {
if (event.getEventType() == ScrollEvent.SCROLL &&
!((ScrollEvent)event).isDirect()) {
tail = tail.prepend(blockEventDispatcher);
tail = tail.prepend(oldVsbEventDispatcher);
return tail.dispatchEvent(event);
}
return oldVsbEventDispatcher.dispatchEvent(event, tail);
}
});
/*
** listen for ScrollEvents over the whole of the VirtualFlow
** area, the above dispatcher having removed the ScrollBars
** scroll event handling.
*/
setOnScroll(new EventHandler() {
@Override public void handle(ScrollEvent event) {
if (PlatformImpl.isSupported(ConditionalFeature.INPUT_TOUCH)) {
if (touchDetected == false && mouseDown == false ) {
startSBReleasedAnimation();
}
}
/*
** calculate the delta in the direction of the flow.
*/
double virtualDelta = 0.0;
if (isVertical()) {
switch(event.getTextDeltaYUnits()) {
case PAGES:
virtualDelta = event.getTextDeltaY() * lastHeight;
break;
case LINES:
/*
** if we've selected a cell, then use
** it's length for the scroll, otherwise
** use the length of the first visible cell
*/
if (lastCellLength != -1) {
virtualDelta = event.getTextDeltaY() * lastCellLength;
}
else if (getFirstVisibleCell() != null) {
virtualDelta = event.getTextDeltaY() * getCellLength(getFirstVisibleCell());
}
break;
case NONE:
virtualDelta = event.getDeltaY();
}
} else { // horizontal
switch(event.getTextDeltaXUnits()) {
case CHARACTERS:
// can we get character size here?
// for now, fall through to pixel values
case NONE:
double dx = event.getDeltaX();
double dy = event.getDeltaY();
virtualDelta = (Math.abs(dx) > Math.abs(dy) ? dx : dy);
}
}
if (virtualDelta != 0.0) {
/*
** only consume it if we use it
*/
adjustPixels(-virtualDelta);
event.consume();
}
else {
/*
** we didn't scroll in the Virtual plane, lets see
** if we scrolled on the other plane.
*/
ScrollBar nonVirtualBar = isVertical() ? hbar : vbar;
if (nonVirtualBar.isVisible()) {
double nonVirtualDelta = isVertical() ? event.getDeltaX() : event.getDeltaY();
double newValue = nonVirtualBar.getValue() - nonVirtualDelta;
if (newValue < nonVirtualBar.getMin()) {
nonVirtualBar.setValue(nonVirtualBar.getMin());
} else if (newValue > nonVirtualBar.getMax()) {
nonVirtualBar.setValue(nonVirtualBar.getMax());
} else {
nonVirtualBar.setValue(newValue);
}
event.consume();
}
}
}
});
addEventFilter(MouseEvent.MOUSE_PRESSED, new EventHandler() {
@Override
public void handle(MouseEvent e) {
mouseDown = true;
if (PlatformImpl.isSupported(ConditionalFeature.INPUT_TOUCH)) {
scrollBarOn();
}
if (isFocusTraversable()) {
requestFocus();
}
lastX = e.getX();
lastY = e.getY();
// determine whether the user has push down on the virtual flow,
// or whether it is the scrollbar. This is done to prevent
// mouse events being 'doubled up' when dragging the scrollbar
// thumb - it has the side-effect of also starting the panning
// code, leading to flicker
isPanning = ! (vbar.getBoundsInParent().contains(e.getX(), e.getY())
|| hbar.getBoundsInParent().contains(e.getX(), e.getY()));
}
});
addEventFilter(MouseEvent.MOUSE_RELEASED, new EventHandler() {
@Override
public void handle(MouseEvent e) {
mouseDown = false;
if (PlatformImpl.isSupported(ConditionalFeature.INPUT_TOUCH)) {
startSBReleasedAnimation();
}
}
});
addEventFilter(MouseEvent.MOUSE_DRAGGED, new EventHandler() {
@Override
public void handle(MouseEvent e) {
if (PlatformImpl.isSupported(ConditionalFeature.INPUT_TOUCH)) {
scrollBarOn();
}
if (! isPanning || ! isPannable()) return;
// With panning enabled, we support panning in both vertical
// and horizontal directions, regardless of the fact that
// VirtualFlow is virtual in only one direction.
double xDelta = lastX - e.getX();
double yDelta = lastY - e.getY();
// figure out the distance that the mouse moved in the virtual
// direction, and then perform the movement along that axis
// virtualDelta will contain the amount we actually did move
double virtualDelta = isVertical() ? yDelta : xDelta;
double actual = adjustPixels(virtualDelta);
if (actual != 0) {
// update last* here, as we know we've just adjusted the
// scrollbar. This means we don't get the situation where a
// user presses-and-drags a long way past the min or max
// values, only to change directions and see the scrollbar
// start moving immediately.
if (isVertical()) lastY = e.getY();
else lastX = e.getX();
}
// similarly, we do the same in the non-virtual direction
double nonVirtualDelta = isVertical() ? xDelta : yDelta;
ScrollBar nonVirtualBar = isVertical() ? hbar : vbar;
if (nonVirtualBar.isVisible()) {
double newValue = nonVirtualBar.getValue() + nonVirtualDelta;
if (newValue < nonVirtualBar.getMin()) {
nonVirtualBar.setValue(nonVirtualBar.getMin());
} else if (newValue > nonVirtualBar.getMax()) {
nonVirtualBar.setValue(nonVirtualBar.getMax());
} else {
nonVirtualBar.setValue(newValue);
// same as the last* comment above
if (isVertical()) lastX = e.getX();
else lastY = e.getY();
}
}
}
});
/*
* We place the scrollbars _above_ the rectangle, such that the drag
* operations often used in conjunction with scrollbars aren't
* misinterpreted as drag operations on the rectangle as well (which
* would be the case if the scrollbars were underneath it as the
* rectangle itself doesn't block the mouse.
*/
// --- vbar
vbar.setOrientation(Orientation.VERTICAL);
vbar.addEventHandler(MouseEvent.ANY, new EventHandler() {
@Override public void handle(MouseEvent event) {
event.consume();
}
});
getChildren().add(vbar);
// --- hbar
hbar.setOrientation(Orientation.HORIZONTAL);
hbar.addEventHandler(MouseEvent.ANY, new EventHandler() {
@Override public void handle(MouseEvent event) {
event.consume();
}
});
getChildren().add(hbar);
// --- corner
corner = new StackPane();
corner.getStyleClass().setAll("corner");
getChildren().add(corner);
// initBinds
// clipView binds
InvalidationListener listenerX = new InvalidationListener() {
@Override public void invalidated(Observable valueModel) {
updateHbar();
}
};
verticalProperty().addListener(listenerX);
hbar.valueProperty().addListener(listenerX);
hbar.visibleProperty().addListener(listenerX);
// ChangeListener listenerY = new ChangeListener() {
// @Override public void handle(Bean bean, PropertyReference property) {
// clipView.setClipY(isVertical() ? 0 : vbar.getValue());
// }
// };
// addChangedListener(VERTICAL, listenerY);
// vbar.addChangedListener(ScrollBar.VALUE, listenerY);
ChangeListener listenerY = new ChangeListener() {
@Override public void changed(ObservableValue ov, Object t, Object t1) {
clipView.setClipY(isVertical() ? 0 : vbar.getValue());
}
};
vbar.valueProperty().addListener(listenerY);
super.heightProperty().addListener(new ChangeListener() {
@Override
public void changed(ObservableValue observable, Number oldHeight, Number newHeight) {
// Fix for RT-8480, where the VirtualFlow does not show its content
// after changing size to 0 and back.
if (oldHeight.doubleValue() == 0 && newHeight.doubleValue() > 0) {
recreateCells();
}
}
});
/*
** there are certain animations that need to know if the touch is
** happening.....
*/
setOnTouchPressed(new EventHandler() {
@Override public void handle(TouchEvent e) {
touchDetected = true;
scrollBarOn();
}
});
setOnTouchReleased(new EventHandler() {
@Override public void handle(TouchEvent e) {
touchDetected = false;
startSBReleasedAnimation();
}
});
}
void updateHbar() {
// Bring the clipView.clipX back to 0 if control is vertical or
// the hbar isn't visible (fix for RT-11666)
if (! isVisible() || getScene() == null) return;
if (isVertical()) {
if (hbar.isVisible()) {
clipView.setClipX(hbar.getValue());
} else {
// all cells are now less than the width of the flow,
// so we should shift the hbar/clip such that
// everything is visible in the viewport.
clipView.setClipX(0);
hbar.setValue(0);
}
}
}
/***************************************************************************
* *
* Layout Functionality *
* *
**************************************************************************/
/**
* Overridden to implement somewhat more efficient support for layout. The
* VirtualFlow can generally be considered as being unmanaged, in that
* whenever the position changes, or other such things change, we need
* to perform a layout but there is no reason to notify the parent. However
* when things change which may impact the preferred size (such as
* vertical, createCell, and configCell) then we need to notify the
* parent.
*/
@Override public void requestLayout() {
// isNeedsLayout() is commented out due to RT-21417. This does not
// appear to impact performance (indeed, it may help), and resolves the
// issue identified in RT-21417.
if (getScene() != null/* && !isNeedsLayout()*/) {
getScene().addToDirtyLayoutList(this);
setNeedsLayout(true);
}
}
@Override protected void layoutChildren() {
if (needsRecreateCells) {
maxPrefBreadth = -1;
lastWidth = -1;
lastHeight = -1;
numCellsVisibleOnScreen = -1;
releaseCell(accumCell);
// accumCell = null;
// accumCellParent.getChildren().clear();
sheet.getChildren().clear();
for (int i = 0, max = cells.size(); i < max; i++) {
cells.get(i).updateIndex(-1);
}
cells.clear();
pile.clear();
} else if (needsRebuildCells) {
maxPrefBreadth = -1;
lastWidth = -1;
lastHeight = -1;
releaseCell(accumCell);
for (int i=0; i lastHeight) || (! isVertical && width > lastWidth)) {
// resized in the virtual direction
needTrailingCells = true;
}
}
updateViewport();
updateScrollBarsAndCells();
// Get the index of the "current" cell
int currentIndex = computeCurrentIndex();
if (lastCellCount != cellCount) {
// The cell count has changed. We want to keep the viewport
// stable if possible. If position was 0 or 1, we want to keep
// the position in the same place. If the new cell count is >=
// the currentIndex, then we will adjust the position to be 1.
// Otherwise, our goal is to leave the index of the cell at the
// top consistent, with the same translation etc.
if (position == 0 || position == 1) {
// Update the item count
// setItemCount(cellCount);
} else if (currentIndex >= cellCount) {
setPosition(1.0f);
// setItemCount(cellCount);
} else if (firstCell != null) {
double firstCellOffset = getCellPosition(firstCell);
int firstCellIndex = firstCell.getIndex();
// setItemCount(cellCount);
adjustPositionToIndex(firstCellIndex);
double viewportTopToCellTop = -computeOffsetForCell(firstCellIndex);
adjustByPixelAmount(viewportTopToCellTop - firstCellOffset);
}
// Update the current index
currentIndex = computeCurrentIndex();
}
if (rebuild) {
// Start by dumping all the cells into the pile
addAllToPile();
// The distance from the top of the viewport to the top of the
// cell for the current index.
double offset = -computeViewportOffset(getPosition());
// Add all the leading and trailing cells (the call to add leading
// cells will add the current cell as well -- that is, the one that
// represents the current position on the mapper).
addLeadingCells(currentIndex, offset);
// Force filling of space with empty cells if necessary
addTrailingCells(true);
} else if (needTrailingCells) {
addTrailingCells(true);
}
updateViewport();
updateScrollBarsAndCells();
lastWidth = getWidth();
lastHeight = getHeight();
lastCellCount = getCellCount();
lastVertical = isVertical();
lastPosition = getPosition();
cleanPile();
}
/**
* Adds all the cells prior to and including the given currentIndex, until
* no more can be added without falling off the flow. The startOffset
* indicates the distance from the leading edge (top) of the viewport to
* the leading edge (top) of the currentIndex.
*/
private void addLeadingCells(int currentIndex, double startOffset) {
// The offset will keep track of the distance from the top of the
// viewport to the top of the current index. We will increment it
// as we lay out leading cells.
double offset = startOffset;
// The index is the absolute index of the cell being laid out
int index = currentIndex;
// Offset should really be the bottom of the current index
boolean first = true; // first time in, we just fudge the offset and let
// it be the top of the current index then redefine
// it as the bottom of the current index thereafter
// while we have not yet laid out so many cells that they would fall
// off the flow, we will continue to create and add cells. The
// offset is our indication of whether we can lay out additional
// cells. If the offset is ever < 0, except in the case of the very
// first cell, then we must quit.
T cell = null;
while (index >= 0 && (offset > 0 || first)) {
cell = getAvailableCell(index);
setCellIndex(cell, index);
resizeCellSize(cell); // resize must be after config
cells.addFirst(cell);
// A little gross but better than alternatives because it reduces
// the number of times we have to update a cell or compute its
// size. The first time into this loop "offset" is actually the
// top of the current index. On all subsequent visits, it is the
// bottom of the current index.
if (first) {
first = false;
} else {
offset -= getCellLength(cell);
}
// Position the cell, and update the maxPrefBreadth variable as we go.
positionCell(cell, offset);
maxPrefBreadth = Math.max(maxPrefBreadth, getCellBreadth(cell));
cell.setVisible(true);
--index;
}
// There are times when after laying out the cells we discover that
// the top of the first cell which represents index 0 is below the top
// of the viewport. In these cases, we have to adjust the cells up
// and reset the mapper position. This might happen when items got
// removed at the top or when the viewport size increased.
cell = cells.getFirst();
int firstIndex = cell.getIndex();
double firstCellPos = getCellPosition(cell);
if (firstIndex == 0 && firstCellPos > 0) {
setPosition(0.0f);
offset = 0;
for (int i = 0; i < cells.size(); i++) {
cell = cells.get(i);
positionCell(cell, offset);
offset += getCellLength(cell);
}
}
}
/**
* Adds all the trailing cells that come after the last index in
* the cells ObservableList.
*/
private boolean addTrailingCells(boolean fillEmptyCells) {
// If cells is empty then addLeadingCells bailed for some reason and
// we're hosed, so just punt
if (cells.isEmpty()) return false;
// While we have not yet laid out so many cells that they would fall
// off the flow, so we will continue to create and add cells. When the
// offset becomes greater than the width/height of the flow, then we
// know we cannot add any more cells.
T startCell = cells.getLast();
double offset = getCellPosition(startCell) + getCellLength(startCell);
int index = startCell.getIndex() + 1;
boolean filledWithNonEmpty = index <= cellCount;
while (offset < viewportLength) {
if (index >= cellCount) {
if (offset < viewportLength) filledWithNonEmpty = false;
if (! fillEmptyCells) return filledWithNonEmpty;
}
T cell = getAvailableCell(index);
setCellIndex(cell, index);
resizeCellSize(cell); // resize happens after config!
cells.addLast(cell);
// Position the cell and update the max pref
positionCell(cell, offset);
maxPrefBreadth = Math.max(maxPrefBreadth, getCellBreadth(cell));
offset += getCellLength(cell);
cell.setVisible(true);
++index;
}
// Discover whether the first cell coincides with index #0. If after
// adding all the trailing cells we find that a) the first cell was
// not index #0 and b) there are trailing cells, then we have a
// problem. We need to shift all the cells down and add leading cells,
// one at a time, until either the very last non-empty cells is aligned
// with the bottom OR we have laid out cell index #0 at the first
// position.
T firstCell = cells.getFirst();
index = firstCell.getIndex();
T lastNonEmptyCell = getLastVisibleCell();
double start = getCellPosition(firstCell);
double end = getCellPosition(lastNonEmptyCell) + getCellLength(lastNonEmptyCell);
if ((index != 0 || (index == 0 && start < 0)) && fillEmptyCells &&
lastNonEmptyCell != null &&lastNonEmptyCell.getIndex() == cellCount - 1 && end < viewportLength) {
double prospectiveEnd = end;
double distance = viewportLength - end;
while (prospectiveEnd < viewportLength && index != 0 && (-start) < distance) {
index--;
T cell = getAvailableCell(index);
setCellIndex(cell, index);
resizeCellSize(cell); // resize must be after config
cells.addFirst(cell);
double cellLength = getCellLength(cell);
start -= cellLength;
prospectiveEnd += cellLength;
positionCell(cell, start);
maxPrefBreadth = Math.max(maxPrefBreadth, getCellBreadth(cell));
cell.setVisible(true);
}
// The amount by which to translate the cells down
firstCell = cells.getFirst();
start = getCellPosition(firstCell);
double delta = viewportLength - end;
if (firstCell.getIndex() == 0 && delta > (-start)) {
delta = (-start);
}
// Move things
for (int i = 0; i < cells.size(); i++) {
T cell = cells.get(i);
positionCell(cell, getCellPosition(cell) + delta);
}
// Check whether the first cell, subsequent to our adjustments, is
// now index #0 and aligned with the top. If so, change the position
// to be at 0 instead of 1.
start = getCellPosition(firstCell);
if (firstCell.getIndex() == 0 && start == 0) {
setPosition(0);
} else if (getPosition() != 1) {
setPosition(1);
}
}
return filledWithNonEmpty;
}
private void updateViewport() {
// Initialize the viewportLength and viewportBreadth to match the
// width/height of the flow
final boolean isVertical = isVertical();
double width = getWidth();
double height = getHeight();
viewportLength = snapSize(isVertical ? height : width);
viewportBreadth = snapSize(isVertical ? width : height);
// Assign the hbar and vbar to the breadthBar and lengthBar so as
// to make some subsequent calculations easier.
VirtualScrollBar breadthBar = isVertical ? hbar : vbar;
VirtualScrollBar lengthBar = isVertical ? vbar : hbar;
double breadthBarLength = snapSize(isVertical ? hbar.prefHeight(-1) : vbar.prefWidth(-1));
double lengthBarBreadth = snapSize(isVertical ? vbar.prefWidth(-1) : hbar.prefHeight(-1));
// If there has been a switch between the virtualized bar, then we
// will want to do some stuff TODO.
breadthBar.setVirtual(false);
lengthBar.setVirtual(true);
// We need to determine whether the hbar and vbar are necessary. If the
// flow has been scrolled in the virtual direction, then we know for
// certain that the virtual scroll bar is required. If the
// maxPrefBreadth is already greater than the viewport, then we know
// we need the breadthBar as well. If neither of these two conditions
// are met, then we need to grab the first page worth of cells and
// compute the maxPrefBreadth and also determine if we have enough cells
// such that it will require more than a single page.
if (maxPrefBreadth == -1) {
return;
}
// Perform a few computations used for understanding the effect of the
// bars on the viewport dimensions. Here we tentatively decide whether
// we need the breadth bar and the length bar.
// The last condition here (viewportLength >= getHeight()) was added to
// resolve the edge-case identified in RT-14350.
boolean needLengthBar = getPosition() > 0 && (cellCount >= cells.size() || viewportLength >= height);
boolean needBreadthBar = maxPrefBreadth > viewportBreadth || (needLengthBar && maxPrefBreadth > (viewportBreadth - lengthBarBreadth));
// Start by optimistically deciding whether the length bar and
// breadth bar are needed and adjust the viewport dimensions
// accordingly. If during layout we find that one or the other of the
// bars actually is needed, then we will perform a cleanup pass
if (!PlatformImpl.isSupported(ConditionalFeature.INPUT_TOUCH)) {
if (needBreadthBar) viewportLength -= breadthBarLength;
if (needLengthBar) viewportBreadth -= lengthBarBreadth;
breadthBar.setVisible(needBreadthBar);
lengthBar.setVisible(needLengthBar);
}
else {
breadthBar.setVisible(needBreadthBar && tempVisibility);
lengthBar.setVisible(needLengthBar && tempVisibility);
}
}
@Override protected void setWidth(double value) {
if (value != lastWidth) {
super.setWidth(value);
setNeedsLayout(true);
requestLayout();
}
}
@Override protected void setHeight(double value) {
if (value != lastHeight) {
super.setHeight(value);
setNeedsLayout(true);
requestLayout();
}
}
private void updateScrollBarsAndCells() {
// Assign the hbar and vbar to the breadthBar and lengthBar so as
// to make some subsequent calculations easier.
final boolean isVertical = isVertical();
VirtualScrollBar breadthBar = isVertical ? hbar : vbar;
VirtualScrollBar lengthBar = isVertical ? vbar : hbar;
double breadthBarLength = snapSize(isVertical ? hbar.prefHeight(-1) : vbar.prefWidth(-1));
double lengthBarBreadth = snapSize(isVertical ? vbar.prefWidth(-1) : hbar.prefHeight(-1));
// Now that we've laid out the cells, we may need to adjust the scroll
// bars and update the viewport dimensions based on the bars
// We have to do the following work twice because the first pass
// through the loop may have made the breadth bar visible, which will
// adjust the viewportLength, which may make the lengthBar need to
// be visible as well.
final int cellsSize = cells.size();
for (int i = 0; i < 2; i++) {
if (! lengthBar.isVisible()) {
// If cellCount is > than cells.size(), then we know we need the
// length bar.
if (cellCount > cellsSize) {
if (!PlatformImpl.isSupported(ConditionalFeature.INPUT_TOUCH)) {
lengthBar.setVisible(true);
}
else {
lengthBar.setVisible(tempVisibility);
}
} else if (cellCount == cellsSize) {
// We must check a corner case here where the cell count
// exactly matches the number of cells laid out. In this case,
// we need to check the last cell's layout position + length
// to determine if we need the length bar
T lastCell = cells.getLast();
if (!PlatformImpl.isSupported(ConditionalFeature.INPUT_TOUCH)) {
lengthBar.setVisible((getCellPosition(lastCell) + getCellLength(lastCell)) > viewportLength);
}
else {
lengthBar.setVisible(((getCellPosition(lastCell) + getCellLength(lastCell)) > viewportLength) && tempVisibility);
}
}
// If the bar is needed, adjust the viewportBreadth
if (lengthBar.isVisible() && !PlatformImpl.isSupported(ConditionalFeature.INPUT_TOUCH)) {
viewportBreadth -= lengthBarBreadth;
}
}
if (! breadthBar.isVisible()) {
final boolean visible = maxPrefBreadth > viewportBreadth;
if (!PlatformImpl.isSupported(ConditionalFeature.INPUT_TOUCH)) {
breadthBar.setVisible(visible);
if (visible) {
viewportLength -= breadthBarLength;
}
}
else {
breadthBar.setVisible(visible && tempVisibility);
}
}
}
// Toggle visibility on the corner
corner.setVisible(breadthBar.isVisible() && lengthBar.isVisible());
double sumCellLength = 0;
double flowLength = (isVertical ? getHeight() : getWidth()) -
(breadthBar.isVisible() ? breadthBar.prefHeight(-1) : 0);
// This was changed from '== -1' to '<= 0' due to RT-29390. If this needs
// to change in the future there are unit tests developed against
// ListView, TreeView, TableView and TreeTableView, so it is hoped that
// RT-29390 will not be reintroduced.
if (numCellsVisibleOnScreen <= 0) {
numCellsVisibleOnScreen = 0;
for (int i = 0, max = cells.size(); i < max; i++) {
T cell = cells.get(i);
if (cell != null && ! cell.isEmpty()) {
sumCellLength += (isVertical ? cell.getHeight() : cell.getWidth());
if (sumCellLength > flowLength) {
break;
}
numCellsVisibleOnScreen++;
}
}
}
// Now position and update the scroll bars
if (breadthBar.isVisible()) {
/*
** Positioning the ScrollBar
*/
if (!PlatformImpl.isSupported(ConditionalFeature.INPUT_TOUCH)) {
if (isVertical) {
hbar.resizeRelocate(0, viewportLength,
viewportBreadth, hbar.prefHeight(viewportBreadth));
} else {
vbar.resizeRelocate(viewportLength, 0,
vbar.prefWidth(viewportBreadth), viewportBreadth);
}
}
else {
if (isVertical) {
hbar.resizeRelocate(0, (viewportLength-hbar.getHeight()),
viewportBreadth, hbar.prefHeight(viewportBreadth));
} else {
vbar.resizeRelocate((viewportLength-vbar.getWidth()), 0,
vbar.prefWidth(viewportBreadth), viewportBreadth);
}
}
// There was a weird bug where the newMax would sometimes go < 0
// when switching vertical and that would drive the min value to
// something crazy negative.
double newMax = Math.max(1, maxPrefBreadth - viewportBreadth);
if (newMax != breadthBar.getMax()) {
breadthBar.setMax(newMax);
double breadthBarValue = breadthBar.getValue();
boolean maxed = breadthBarValue != 0 && newMax == breadthBarValue;
if (maxed || breadthBarValue > newMax) {
breadthBar.setValue(newMax);
}
breadthBar.setVisibleAmount((viewportBreadth / maxPrefBreadth) * newMax);
}
}
if (lengthBar.isVisible()) {
lengthBar.setMax(1);
if (numCellsVisibleOnScreen == 0 && cellCount == 1) {
// special case to help resolve RT-17701 and the case where we have
// only a single row and it is bigger than the viewport
lengthBar.setVisibleAmount(flowLength / sumCellLength);
} else {
lengthBar.setVisibleAmount(numCellsVisibleOnScreen / (float) cellCount);
}
// Fix for RT-11873. If this isn't here, we can have a situation where
// the scrollbar scrolls endlessly. This is possible when the cell
// count grows as the user hits the maximal position on the scrollbar
// (i.e. the list size dynamically grows as the user needs more).
//
// This code was commented out to resolve RT-14477 after testing
// whether RT-11873 can be recreated. It could not, and therefore
// for now this code will remained uncommented until it is deleted
// following further testing.
// if (lengthBar.getValue() == 1.0 && lastCellCount != cellCount) {
// lengthBar.setValue(0.99);
// }
/*
** Positioning the ScrollBar
*/
if (!PlatformImpl.isSupported(ConditionalFeature.INPUT_TOUCH)) {
if (isVertical) {
vbar.resizeRelocate(viewportBreadth, 0, vbar.prefWidth(viewportLength), viewportLength);
} else {
hbar.resizeRelocate(0, viewportBreadth, viewportLength, hbar.prefHeight(-1));
}
}
else {
if (isVertical) {
vbar.resizeRelocate((viewportBreadth-vbar.getWidth()), 0, vbar.prefWidth(viewportLength), viewportLength);
} else {
hbar.resizeRelocate(0, (viewportBreadth-hbar.getHeight()), viewportLength, hbar.prefHeight(-1));
}
}
}
if (corner.isVisible()) {
if (!PlatformImpl.isSupported(ConditionalFeature.INPUT_TOUCH)) {
corner.resize(vbar.getWidth(), hbar.getHeight());
corner.relocate(hbar.getLayoutX() + hbar.getWidth(), vbar.getLayoutY() + vbar.getHeight());
}
else {
corner.resize(vbar.getWidth(), hbar.getHeight());
corner.relocate(hbar.getLayoutX() + (hbar.getWidth()-vbar.getWidth()), vbar.getLayoutY() + (vbar.getHeight()-hbar.getHeight()));
hbar.resize(hbar.getWidth()-vbar.getWidth(), hbar.getHeight());
vbar.resize(vbar.getWidth(), vbar.getHeight()-hbar.getHeight());
}
}
clipView.resize(snapSize(isVertical ? viewportBreadth : viewportLength),
snapSize(isVertical ? viewportLength : viewportBreadth));
// We may have adjusted the viewport length and breadth after the
// layout due to scroll bars becoming visible. So we need to perform
// a follow up pass and resize and shift all the cells to fit the
// viewport. Note that the prospective viewport size is always >= the
// final viewport size, so we don't have to worry about adding
// cells during this cleanup phase.
fitCells();
// If the viewportLength becomes large enough that all cells fit
// within the viewport, then we want to update the value to match.
if (getPosition() != lengthBar.getValue()) {
lengthBar.setValue(getPosition());
}
}
/**
* Adjusts the cells location and size if necessary. The breadths of all
* cells will be adjusted to fit the viewportWidth or maxPrefBreadth, and
* the layout position will be updated if necessary based on index and
* offset.
*/
private void fitCells() {
double size = Math.max(maxPrefBreadth, viewportBreadth);
boolean isVertical = isVertical();
for (int i = 0, max = cells.size(); i < max; i++) {
Cell cell = cells.get(i);
if (isVertical) {
cell.resize(size, cell.getHeight());
} else {
cell.resize(cell.getWidth(), size);
}
}
}
private void cull() {
for (int i = cells.size() - 1; i >= 0; i--) {
T cell = cells.get(i);
double cellSize = getCellLength(cell);
double cellStart = getCellPosition(cell);
double cellEnd = cellStart + cellSize;
if (cellStart > viewportLength || cellEnd < 0) {
addToPile(cells.remove(i));
}
}
}
/***************************************************************************
* *
* Helper functions for working with cells *
* *
**************************************************************************/
/**
* Return a cell for the given index. This may be called for any cell,
* including beyond the range defined by cellCount, in which case an
* empty cell will be returned. The returned value should not be stored for
* any reason.
*/
public T getCell(int index) {
// If there are cells, then we will attempt to get an existing cell
if (! cells.isEmpty()) {
// First check the cells that have already been created and are
// in use. If this call returns a value, then we can use it
T cell = getVisibleCell(index);
if (cell != null) return cell;
}
// check the pile
for (int i = 0; i < pile.size(); i++) {
T cell = pile.get(i);
if (cell.getIndex() == index) {
// Note that we don't remove from the pile: if we do it leads
// to a severe performance decrease. This seems to be OK, as
// getCell() is only used for cell measurement purposes.
// pile.remove(i);
return cell;
}
}
if (pile.size() > 0) {
accumCell = pile.get(0);
}
// We need to use the accumCell and return that
if (accumCell == null) {
Callback createCell = getCreateCell();
if (createCell != null) {
accumCell = createCell.call(this);
accumCell.getProperties().put(NEW_CELL, null);
accumCellParent.getChildren().setAll(accumCell);
}
}
setCellIndex(accumCell, index);
resizeCellSize(accumCell);
return accumCell;
}
/**
* After using the accum cell, it needs to be released!
*/
private void releaseCell(T cell) {
if (accumCell != null && cell == accumCell) {
accumCell.updateIndex(-1);
}
}
/**
* Compute and return the length of the cell for the given index. This is
* called both internally when adjusting by pixels, and also at times
* by PositionMapper (see the getItemSize callback). When called by
* PositionMapper, it is possible that it will be called for some index
* which is not associated with any cell, so we have to do a bit of work
* to use a cell as a helper for computing cell size in some cases.
*/
double getCellLength(int index) {
if (fixedCellSizeEnabled) return fixedCellSize;
T cell = getCell(index);
double length = getCellLength(cell);
releaseCell(cell);
return length;
}
/**
*/
double getCellBreadth(int index) {
T cell = getCell(index);
double b = getCellBreadth(cell);
releaseCell(cell);
return b;
}
/**
* Gets the length of a specific cell
*/
private double getCellLength(T cell) {
if (cell == null) return 0;
if (fixedCellSizeEnabled) return fixedCellSize;
return isVertical() ?
cell.getLayoutBounds().getHeight()
: cell.getLayoutBounds().getWidth();
}
// private double getCellPrefLength(T cell) {
// return isVertical() ?
// cell.prefHeight(-1)
// : cell.prefWidth(-1);
// }
/**
* Gets the breadth of a specific cell
*/
private double getCellBreadth(Cell cell) {
return isVertical() ?
cell.prefWidth(-1)
: cell.prefHeight(-1);
}
/**
* Gets the layout position of the cell along the length axis
*/
private double getCellPosition(T cell) {
if (cell == null) return 0;
return isVertical() ?
cell.getLayoutY()
: cell.getLayoutX();
}
private void positionCell(T cell, double position) {
if (isVertical()) {
cell.setLayoutX(0);
cell.setLayoutY(snapSize(position));
} else {
cell.setLayoutX(snapSize(position));
cell.setLayoutY(0);
}
}
private void resizeCellSize(T cell) {
if (cell == null) return;
if (isVertical()) {
double width = cell.getWidth();
cell.resize(width, fixedCellSizeEnabled ? fixedCellSize : cell.prefHeight(width));
} else {
double height = cell.getHeight();
cell.resize(fixedCellSizeEnabled ? fixedCellSize : cell.prefWidth(height), height);
}
}
private void setCellIndex(T cell, int index) {
assert cell != null;
cell.updateIndex(index);
if (cell.isNeedsLayout() && cell.getScene() != null && cell.getProperties().containsKey(NEW_CELL)) {
cell.impl_processCSS(false);
cell.getProperties().remove(NEW_CELL);
}
}
/***************************************************************************
* *
* Helper functions for cell management *
* *
**************************************************************************/
/**
* Indicates that this is a newly created cell and we need call impl_processCSS for it.
*
* See RT-23616 for more details.
*/
private static final String NEW_CELL = "newcell";
/**
* Get a cell which can be used in the layout. This function will reuse
* cells from the pile where possible, and will create new cells when
* necessary.
*/
private T getAvailableCell(int prefIndex) {
T cell = null;
// Fix for RT-12822. We try to retrieve the cell from the pile rather
// than just grab a random cell from the pile (or create another cell).
for (int i = 0, max = pile.size(); i < max; i++) {
T _cell = pile.get(i);
assert _cell != null;
if (_cell.getIndex() == prefIndex) {
cell = _cell;
pile.remove(i);
break;
}
cell = null;
}
if (cell == null) {
if (pile.size() > 0) {
// we try to get a cell with an index that is the same even/odd
// as the prefIndex. This saves us from having to run so much
// css on the cell as it will not change from even to odd, or
// vice versa
final boolean prefIndexIsEven = (prefIndex & 1) == 0;
for (int i = 0, max = pile.size(); i < max; i++) {
final T c = pile.get(i);
final int cellIndex = c.getIndex();
if ((cellIndex & 1) == 0 && prefIndexIsEven) {
cell = c;
pile.remove(i);
break;
} else if ((cellIndex & 1) == 1 && ! prefIndexIsEven) {
cell = c;
pile.remove(i);
break;
}
}
if (cell == null) {
cell = pile.removeFirst();
}
} else {
cell = createCell.call(this);
cell.getProperties().put(NEW_CELL, null);
}
}
if (cell.getParent() == null) {
sheetChildren.add(cell);
}
return cell;
}
private void addAllToPile() {
for (int i = 0, max = cells.size(); i < max; i++) {
addToPile(cells.removeFirst());
}
}
/**
* Puts the given cell onto the pile. This is called whenever a cell has
* fallen off the flow's start.
*/
private void addToPile(T cell) {
assert cell != null;
pile.addLast(cell);
}
private void cleanPile() {
for (int i = 0, max = pile.size(); i < max; i++) {
T cell = pile.get(i);
cell.setVisible(false);
}
}
/**
* Gets a cell for the given index if the cell has been created and laid out.
* "Visible" is a bit of a misnomer, the cell might not be visible in the
* viewport (it may be clipped), but does distinguish between cells that
* have been created and are in use vs. those that are in the pile or
* not created.
*/
public T getVisibleCell(int index) {
if (cells.isEmpty()) return null;
// check the last index
T lastCell = cells.getLast();
int lastIndex = lastCell.getIndex();
if (index == lastIndex) return lastCell;
// check the first index
T firstCell = cells.getFirst();
int firstIndex = firstCell.getIndex();
if (index == firstIndex) return firstCell;
// if index is > firstIndex and < lastIndex then we can get the index
if (index > firstIndex && index < lastIndex) {
return cells.get(index - firstIndex);
}
// there is no visible cell for the specified index
return null;
}
/**
* Locates and returns the last non-empty IndexedCell that is currently
* partially or completely visible. This function may return null if there
* are no cells, or if the viewport length is 0.
*/
public T getLastVisibleCell() {
if (cells.isEmpty() || viewportLength <= 0) return null;
T cell;
for (int i = cells.size() - 1; i >= 0; i--) {
cell = cells.get(i);
if (! cell.isEmpty()) {
return cell;
}
}
return null;
}
/**
* Locates and returns the first non-empty IndexedCell that is partially or
* completely visible. This really only ever returns null if there are no
* cells or the viewport length is 0.
*/
public T getFirstVisibleCell() {
if (cells.isEmpty() || viewportLength <= 0) return null;
T cell = cells.getFirst();
return cell.isEmpty() ? null : cell;
}
public T getLastVisibleCellWithinViewPort() {
if (cells.isEmpty() || viewportLength <= 0) return null;
T cell;
for (int i = cells.size() - 1; i >= 0; i--) {
cell = cells.get(i);
if (cell.isEmpty()) continue;
if (cell.getLayoutY() < getHeight()) {
return cell;
}
}
return null;
}
public T getFirstVisibleCellWithinViewPort() {
if (cells.isEmpty() || viewportLength <= 0) return null;
final boolean isVertical = isVertical();
T cell;
for (int i = 0; i < cells.size(); i++) {
cell = cells.get(i);
if (cell.isEmpty()) continue;
if (isVertical && cell.getLayoutY() + cell.getHeight() > 0) {
return cell;
} else if (! isVertical && cell.getLayoutX() + cell.getWidth() > 0) {
return cell;
}
}
return null;
}
/**
* Adjust the position of cells so that the specified cell
* will be positioned at the start of the viewport. The given cell must
* already be "live". This is bad public API!
*/
public void showAsFirst(T firstCell) {
if (firstCell != null) {
adjustPixels(getCellPosition(firstCell));
}
}
/**
* Adjust the position of cells so that the specified cell
* will be positioned at the end of the viewport. The given cell must
* already be "live". This is bad public API!
*/
public void showAsLast(T lastCell) {
if (lastCell != null) {
adjustPixels(getCellPosition(lastCell) + getCellLength(lastCell) - viewportLength);
}
}
/**
* Adjusts the cells such that the selected cell will be fully visible in
* the viewport (but only just).
*/
public void show(T cell) {
if (cell != null) {
double start = getCellPosition(cell);
double length = getCellLength(cell);
double end = start + length;
if (start < 0) {
adjustPixels(start);
} else if (end > viewportLength) {
adjustPixels(end - viewportLength);
}
}
}
public void show(int index) {
T cell = getVisibleCell(index);
if (cell != null) {
show(cell);
} else {
// See if the previous index is a visible cell
T prev = getVisibleCell(index - 1);
if (prev != null) {
// Need to add a new cell and then we can show it
// layingOut = true;
cell = getAvailableCell(index);
setCellIndex(cell, index);
resizeCellSize(cell); // resize must be after config
cells.addLast(cell);
positionCell(cell, getCellPosition(prev) + getCellLength(prev));
maxPrefBreadth = Math.max(maxPrefBreadth, getCellBreadth(cell));
cell.setVisible(true);
show(cell);
// layingOut = false;
return;
}
// See if the next index is a visible cell
T next = getVisibleCell(index + 1);
if (next != null) {
// layingOut = true;
cell = getAvailableCell(index);
setCellIndex(cell, index);
resizeCellSize(cell); // resize must be after config
cells.addFirst(cell);
positionCell(cell, getCellPosition(next) - getCellLength(cell));
maxPrefBreadth = Math.max(maxPrefBreadth, getCellBreadth(cell));
cell.setVisible(true);
show(cell);
// layingOut = false;
return;
}
// In this case, we're asked to show a random cell
// layingOut = true;
adjustPositionToIndex(index);
addAllToPile();
requestLayout();
// layingOut = false;
}
}
public void scrollTo(int index) {
boolean posSet = false;
if (index >= cellCount - 1) {
setPosition(1);
posSet = true;
} else if (index < 0) {
setPosition(0);
posSet = true;
}
if (! posSet) {
adjustPositionToIndex(index);
double offset = - computeOffsetForCell(index);
adjustByPixelAmount(offset);
}
requestLayout();
}
//TODO We assume all the cell have the same length. We will need to support
// cells of different lengths.
public void scrollToOffset(int offset) {
adjustPixels(offset * getCellLength(0));
}
/**
* Given a delta value representing a number of pixels, this method attempts
* to move the VirtualFlow in the given direction (positive is down/right,
* negative is up/left) the given number of pixels. It returns the number of
* pixels actually moved.
*/
public double adjustPixels(final double delta) {
// Short cut this method for cases where nothing should be done
if (delta == 0) return 0;
final boolean isVertical = isVertical();
if ((isVertical && ! vbar.isVisible()) || (! isVertical && ! hbar.isVisible())) return 0;
double pos = getPosition();
if (pos == 0.0f && delta < 0) return 0;
if (pos == 1.0f && delta > 0) return 0;
adjustByPixelAmount(delta);
if (pos == getPosition()) {
// The pos hasn't changed, there's nothing to do. This is likely
// to occur when we hit either extremity
return 0;
}
// Now move stuff around. Translating by pixels fundamentally means
// moving the cells by the delta. However, after having
// done that, we need to go through the cells and see which cells,
// after adding in the translation factor, now fall off the viewport.
// Also, we need to add cells as appropriate to the end (or beginning,
// depending on the direction of travel).
//
// One simplifying assumption (that had better be true!) is that we
// will only make it this far in the function if the virtual scroll
// bar is visible. Otherwise, we never will pixel scroll. So as we go,
// if we find that the maxPrefBreadth exceeds the viewportBreadth,
// then we will be sure to show the breadthBar and update it
// accordingly.
int cellsSize = cells.size();
if (cellsSize > 0) {
for (int i = 0; i < cellsSize; i++) {
T cell = cells.get(i);
positionCell(cell, getCellPosition(cell) - delta);
}
// Add any necessary leading cells
T firstCell = cells.getFirst();
int firstIndex = firstCell.getIndex();
double prevIndexSize = getCellLength(firstIndex - 1);
addLeadingCells(firstIndex - 1, getCellPosition(firstCell) - prevIndexSize);
// Starting at the tail of the list, loop adding cells until
// all the space on the table is filled up. We want to make
// sure that we DO NOT add empty trailing cells (since we are
// in the full virtual case and so there are no trailing empty
// cells).
if (! addTrailingCells(false)) {
// Reached the end, but not enough cells to fill up to
// the end. So, remove the trailing empty space, and translate
// the cells down
T lastCell = getLastVisibleCell();
double lastCellSize = getCellLength(lastCell);
double cellEnd = getCellPosition(lastCell) + lastCellSize;
if (cellEnd < viewportLength) {
// Reposition the nodes
double emptySize = viewportLength - cellEnd;
for (int i = 0; i < cells.size(); i++) {
T cell = cells.get(i);
positionCell(cell, getCellPosition(cell) + emptySize);
}
setPosition(1.0f);
}
}
// Now throw away any cells that don't fit
cull();
}
// Finally, update the scroll bars
updateScrollBarsAndCells();
lastPosition = getPosition();
// notify
return delta; // TODO fake
}
private boolean needsReconfigureCells = false; // when cell contents are the same
private boolean needsRecreateCells = false; // when cell factory changed
private boolean needsRebuildCells = false; // when cell contents have changed
private boolean needsCellsLayout = false;
public void reconfigureCells() {
needsReconfigureCells = true;
requestLayout();
}
public void recreateCells() {
needsRecreateCells = true;
requestLayout();
}
public void rebuildCells() {
needsRebuildCells = true;
requestLayout();
}
public void requestCellLayout() {
needsCellsLayout = true;
requestLayout();
}
private static final double GOLDEN_RATIO_MULTIPLIER = 0.618033987;
private double getPrefBreadth(double oppDimension) {
double max = getMaxCellWidth(10);
// This primarily exists for the case where we do not want the breadth
// to grow to ensure a golden ratio between width and height (for example,
// when a ListView is used in a ComboBox - the width should not grow
// just because items are being added to the ListView)
if (oppDimension > -1) {
double prefLength = getPrefLength();
max = Math.max(max, prefLength * GOLDEN_RATIO_MULTIPLIER);
}
return max;
}
private double getPrefLength() {
double sum = 0.0;
int rows = Math.min(10, cellCount);
for (int i = 0; i < rows; i++) {
sum += getCellLength(i);
}
return sum;
}
@Override protected double computePrefWidth(double height) {
double w = isVertical() ? getPrefBreadth(height) : getPrefLength();
return w + vbar.prefWidth(-1);
}
@Override protected double computePrefHeight(double width) {
double h = isVertical() ? getPrefLength() : getPrefBreadth(width);
return h + hbar.prefHeight(-1);
}
double getMaxCellWidth(int rowsToCount) {
double max = 0.0;
// we always measure at least one row
int rows = Math.max(1, rowsToCount == -1 ? cellCount : rowsToCount);
for (int i = 0; i < rows; i++) {
max = Math.max(max, getCellBreadth(i));
}
return max;
}
// Old PositionMapper
/**
* Given a position value between 0 and 1, compute and return the viewport
* offset from the "current" cell associated with that position value.
* That is, if the return value of this function where used as a translation
* factor for a sheet that contained all the items, then the current
* item would end up positioned correctly.
*/
private double computeViewportOffset(double position) {
double p = com.sun.javafx.Utils.clamp(0, position, 1);
double fractionalPosition = p * getCellCount();
int cellIndex = (int) fractionalPosition;
double fraction = fractionalPosition - cellIndex;
double cellSize = getCellLength(cellIndex);
double pixelOffset = cellSize * fraction;
double viewportOffset = viewportLength * p;
return pixelOffset - viewportOffset;
}
private void adjustPositionToIndex(int index) {
int cellCount = getCellCount();
if (cellCount <= 0) {
setPosition(0.0f);
} else {
setPosition(((double)index) / cellCount);
}
}
/**
* Adjust the position based on a delta of pixels. If negative, then the
* position will be adjusted negatively. If positive, then the position will
* be adjusted positively. If the pixel amount is too great for the range of
* the position, then it will be clamped such that position is always
* strictly between 0 and 1
*/
private void adjustByPixelAmount(double numPixels) {
if (numPixels == 0) return;
// Starting from the current cell, we move in the direction indicated
// by numPixels one cell at a team. For each cell, we discover how many
// pixels the "position" line would move within that cell, and adjust
// our count of numPixels accordingly. When we come to the "final" cell,
// then we can take the remaining number of pixels and multiply it by
// the "travel rate" of "p" within that cell to get the delta. Add
// the delta to "p" to get position.
// get some basic info about the list and the current cell
boolean forward = numPixels > 0;
int cellCount = getCellCount();
double fractionalPosition = getPosition() * cellCount;
int cellIndex = (int) fractionalPosition;
if (forward && cellIndex == cellCount) return;
double cellSize = getCellLength(cellIndex);
double fraction = fractionalPosition - cellIndex;
double pixelOffset = cellSize * fraction;
// compute the percentage of "position" that represents each cell
double cellPercent = 1.0 / cellCount;
// To help simplify the algorithm, we pretend as though the current
// position is at the beginning of the current cell. This reduces some
// of the corner cases and provides a simpler algorithm without adding
// any overhead to performance.
double start = computeOffsetForCell(cellIndex);
double end = cellSize + computeOffsetForCell(cellIndex + 1);
// We need to discover the distance that the fictional "position line"
// would travel within this cell, from its current position to the end.
double remaining = end - start;
// Keep track of the number of pixels left to travel
double n = forward ?
numPixels + pixelOffset - (viewportLength * getPosition()) - start
: -numPixels + end - (pixelOffset - (viewportLength * getPosition()));
// "p" represents the most recent value for position. This is always
// based on the edge between two cells, except at the very end of the
// algorithm where it is added to the computed "p" offset for the final
// value of Position.
double p = cellPercent * cellIndex;
// Loop over the cells one at a time until either we reach the end of
// the cells, or we find that the "n" will fall within the cell we're on
while (n > remaining && ((forward && cellIndex < cellCount - 1) || (! forward && cellIndex > 0))) {
if (forward) cellIndex++; else cellIndex--;
n -= remaining;
cellSize = getCellLength(cellIndex);
start = computeOffsetForCell(cellIndex);
end = cellSize + computeOffsetForCell(cellIndex + 1);
remaining = end - start;
p = cellPercent * cellIndex;
}
// if remaining is < n, then we must have hit an end, so as a
// fast path, we can just set position to 1.0 or 0.0 and return
// because we know we hit the end
if (n > remaining) {
setPosition(forward ? 1.0f : 0.0f);
} else if (forward) {
double rate = cellPercent / Math.abs(end - start);
setPosition(p + (rate * n));
} else {
double rate = cellPercent / Math.abs(end - start);
setPosition((p + cellPercent) - (rate * n));
}
}
private int computeCurrentIndex() {
return (int) (getPosition() * getCellCount());
}
/**
* Given an item index, this function will compute and return the viewport
* offset from the beginning of the specified item. Notice that because each
* item has the same percentage of the position dedicated to it, and since
* we are measuring from the start of each item, this is a very simple
* calculation.
*/
private double computeOffsetForCell(int itemIndex) {
double cellCount = getCellCount();
double p = com.sun.javafx.Utils.clamp(0, itemIndex, cellCount) / cellCount;
return -(viewportLength * p);
}
// /**
// * Adjust the position based on a chunk of pixels. The position is based
// * on the start of the scrollbar position.
// */
// private void adjustByPixelChunk(double numPixels) {
// setPosition(0);
// adjustByPixelAmount(numPixels);
// }
// end of old PositionMapper code
/**
* A simple extension to Region that ensures that anything wanting to flow
* outside of the bounds of the Region is clipped.
*/
static class ClippedContainer extends Region {
/**
* The Node which is embedded within this {@code ClipView}.
*/
private Node node;
public Node getNode() { return this.node; }
public void setNode(Node n) {
this.node = n;
getChildren().clear();
getChildren().add(node);
}
public void setClipX(double clipX) {
setLayoutX(-clipX);
clipRect.setLayoutX(clipX);
}
public void setClipY(double clipY) {
setLayoutY(-clipY);
clipRect.setLayoutY(clipY);
}
private final Rectangle clipRect;
public ClippedContainer(final VirtualFlow flow) {
if (flow == null) {
throw new IllegalArgumentException("VirtualFlow can not be null");
}
getStyleClass().add("clipped-container");
// clipping
clipRect = new Rectangle();
clipRect.setSmooth(false);
setClip(clipRect);
// --- clipping
super.widthProperty().addListener(new InvalidationListener() {
@Override public void invalidated(Observable valueModel) {
clipRect.setWidth(getWidth());
}
});
super.heightProperty().addListener(new InvalidationListener() {
@Override public void invalidated(Observable valueModel) {
clipRect.setHeight(getHeight());
}
});
}
}
/**
* A List-like implementation that is exceedingly efficient for the purposes
* of the VirtualFlow. Typically there is not much variance in the number of
* cells -- it is always some reasonably consistent number. Yet for efficiency
* in code, we like to use a linked list implementation so as to append to
* start or append to end. However, at times when we need to iterate, LinkedList
* is expensive computationally as well as requiring the construction of
* temporary iterators.
*
* This linked list like implementation is done using an array. It begins by
* putting the first item in the center of the allocated array, and then grows
* outward (either towards the first or last of the array depending on whether
* we are inserting at the head or tail). It maintains an index to the start
* and end of the array, so that it can efficiently expose iteration.
*
* This class is package private solely for the sake of testing.
*/
static class ArrayLinkedList {
/**
* The array list backing this class. We default the size of the array
* list to be fairly large so as not to require resizing during normal
* use, and since that many ArrayLinkedLists won't be created it isn't
* very painful to do so.
*/
private final ArrayList array;
private int firstIndex = -1;
private int lastIndex = -1;
public ArrayLinkedList() {
array = new ArrayList(50);
for (int i = 0; i < 50; i++) {
array.add(null);
}
}
public T getFirst() {
return firstIndex == -1 ? null : array.get(firstIndex);
}
public T getLast() {
return lastIndex == -1 ? null : array.get(lastIndex);
}
public void addFirst(T cell) {
// if firstIndex == -1 then that means this is the first item in the
// list and we need to initialize firstIndex and lastIndex
if (firstIndex == -1) {
firstIndex = lastIndex = array.size() / 2;
array.set(firstIndex, cell);
} else if (firstIndex == 0) {
// we're already at the head of the array, so insert at position
// 0 and then increment the lastIndex to compensate
array.add(0, cell);
lastIndex++;
} else {
// we're not yet at the head of the array, so insert at the
// firstIndex - 1 position and decrement first position
array.set(--firstIndex, cell);
}
}
public void addLast(T cell) {
// if lastIndex == -1 then that means this is the first item in the
// list and we need to initialize the firstIndex and lastIndex
if (firstIndex == -1) {
firstIndex = lastIndex = array.size() / 2;
array.set(lastIndex, cell);
} else if (lastIndex == array.size() - 1) {
// we're at the end of the array so need to "add" so as to force
// the array to be expanded in size
array.add(++lastIndex, cell);
} else {
array.set(++lastIndex, cell);
}
}
public int size() {
return firstIndex == -1 ? 0 : lastIndex - firstIndex + 1;
}
public boolean isEmpty() {
return firstIndex == -1;
}
public T get(int index) {
if (index > (lastIndex - firstIndex) || index < 0) {
// Commented out exception due to RT-29111
// throw new java.lang.ArrayIndexOutOfBoundsException();
return null;
}
return array.get(firstIndex + index);
}
public void clear() {
for (int i = 0; i < array.size(); i++) {
array.set(i, null);
}
firstIndex = lastIndex = -1;
}
public T removeFirst() {
if (isEmpty()) return null;
return remove(0);
}
public T removeLast() {
if (isEmpty()) return null;
return remove(lastIndex - firstIndex);
}
public T remove(int index) {
if (index > lastIndex - firstIndex || index < 0) {
throw new java.lang.ArrayIndexOutOfBoundsException();
}
// if the index == 0, then we're removing the first
// item and can simply set it to null in the array and increment
// the firstIndex unless there is only one item, in which case
// we have to also set first & last index to -1.
if (index == 0) {
T cell = array.get(firstIndex);
array.set(firstIndex, null);
if (firstIndex == lastIndex) {
firstIndex = lastIndex = -1;
} else {
firstIndex++;
}
return cell;
} else if (index == lastIndex - firstIndex) {
// if the index == lastIndex - firstIndex, then we're removing the
// last item and can simply set it to null in the array and
// decrement the lastIndex
T cell = array.get(lastIndex);
array.set(lastIndex--, null);
return cell;
} else {
// if the index is somewhere in between, then we have to remove the
// item and decrement the lastIndex
T cell = array.get(firstIndex + index);
array.set(firstIndex + index, null);
for (int i = (firstIndex + index + 1); i <= lastIndex; i++) {
array.set(i - 1, array.get(i));
}
array.set(lastIndex--, null);
return cell;
}
}
}
Timeline sbTouchTimeline;
KeyFrame sbTouchKF1;
KeyFrame sbTouchKF2;
Timeline contentsToViewTimeline;
KeyFrame contentsToViewKF1;
KeyFrame contentsToViewKF2;
KeyFrame contentsToViewKF3;
private boolean tempVisibility = false;
protected void startSBReleasedAnimation() {
if (sbTouchTimeline == null) {
/*
** timeline to leave the scrollbars visible for a short
** while after a scroll/drag
*/
sbTouchTimeline = new Timeline();
sbTouchKF1 = new KeyFrame(Duration.millis(0), new EventHandler() {
@Override public void handle(ActionEvent event) {
tempVisibility = true;
requestLayout();
}
});
sbTouchKF2 = new KeyFrame(Duration.millis(500), new EventHandler() {
@Override public void handle(ActionEvent event) {
if (touchDetected == false && mouseDown == false) {
tempVisibility = false;
requestLayout();
}
}
});
sbTouchTimeline.getKeyFrames().addAll(sbTouchKF1, sbTouchKF2);
}
sbTouchTimeline.playFromStart();
}
protected void scrollBarOn() {
tempVisibility = true;
requestLayout();
}
}